More than 1,800 people have died from the mosquito-borne viral illness, up from over 1,000 deaths reported last month in the year through March
Trump Jr tested positive at the start of the week and has been "quarantining at his cabin since the result," the spokesman said.
"He's been completely asymptomatic so far and is following all medically recommended COVID-19 guidelines," he said.
Andrew Giuliani, the son of the president's personal lawyer Rudy Giuliani, also said he tested positive for COVID-19 on Friday.